Antibiotics are specific for the type of bacteria being treated and, in general, cannot be interchanged from one infection to another. When antibiotics are used correctly, they are usually safe with few side effects.
However, as with most drugs, antibiotics can lead to side effects that may range from being a nuisance to serious or life-threatening. In infants and the elderly, , in patients with kidney or liver disease, in pregnant or breastfeeding women, and in many other patient groups antibiotic doses may need to be adjusted based upon the specific characteristics of the patient, like kidney or liver function, weight, or age. Drug interactions can also be common with antibiotics. Health care providers are able to assess each patient individually to determine the correct antibiotic and dose.